Diastereoselective synthesis of cis-fused pyrano[4,5-c]pyrrole derivatives via microwave-accelerated intramolecular Knoevenagal hetero Diels-Alder reaction

The synthesis of enantiomerically pure pyrano[4,5-c]pyrroles has been accomplished by the intramolecular hetero Diels-Alder reaction of enantiomerically pure N-allyltetheredalkenyl aldehydes with various 1,3-diones. The reaction led to the formation of cis-fused enantiomerically pure pyrano[4,5-c]pyrroles in excellent yield under mild conditions and the products were characterized by spectroscopic data.